BOOK II. 

 HISTOLOGICAL BOTANY. 



INTRODUCTION. 



All parts of all plants, although they are of various sizes 

 and shapes, may, when examined under the microscope, be 

 found to consist of one or more minute sac-like structures. 

 These minute bodies are called Cells. 



CHAPTER I. 



THE CELL. 



The Cell is the elementary organ of which the fabric of 

 plants is constructed and is usually more or less sac-like. 



Section 1. PARTS OF THE CELL. 



If very thin sections are made of the white portions of 

 the leaves of the Negi and examined under the microscope, 

 it will be seen that they are composed of many quadrangu- 

 lar cells, each of which consists of a clear membrane, 

 a layer of granular semifluid substance lying in contact 

 with the inner surface of the latter, a small globular body 

 imbedded in the semifluid substance, and one or more drops 

 of watery fluid. (See Kg. 110.) The membrane is called 

 the Cell-wall; the semifluid substance, the Protoplasm; 

 the globular body in the latter, the Nucleus ; and the watery 

 fluid, the Cell-sap. 



